## Consumer Math

January 5, 2016 Leave a comment

#### Leslie Green’s Question

The more debt you get into, the more credit card companies profit. If you buy $100 of goods at a shop you owe the credit card company $100, but typically the shop only gets $98. The shop has to inflate its prices to pay the credit card company. Typically the shop is contractually not allowed to give a discount for cash. The CostCrashers supermarket chain deals only in cash. The CardPayers supermarkets deal with both cash and credit card transactions, although 75% of people pay by credit card. All else being equal, how much cheaper could the CostCrashers prices be compared to the CardPayers supermarkets, given the figures stated earlier?

**Stephen Stead’s Dilemma**

My car uses 10 litres / 100 km and has a 70-litre tank. The Village Garage sells fuel for $1.40 per litre. It is just several meters from my house. Several garages outside the village sell fuel for $1.36 per litre. How far could the garage be so that it is worthwhile to drive to and back from the garage to refuel?

#### Income

Bob works 40 years. He does not work on weekends and has a 3-week summer vacation and 7 days of official holidays. The average hourly rate is $12.5 and he works 8 hours per day. What is his total income?

#### Stock Price

Every day, a stock price of $444 is either increased or decreased by 4%. When can it be $444 again?

#### Inflation

If there is a 500% inflation in a country how much will a 2-dollar telephone cost in one year?

#### Discount

Two successive increases of 25% and 25% are followed by two successive discounts of 25% and 25%. What percentage is the result?

#### Selling Luxury Cars

If 2 salesmen can sell three luxury cars in 4 days, how many luxury cars can five salesmen sell to six clients in 7 days?

#### Ratio 1 : 2 : 3

Divide $132 into a ratio 1:2:3. What are the parts?

#### Rebate

Buy 2 for the price of 3 and get 50% off! What is the final rebate do you get?

You find the answers to these and hundreds other Consumer Math’s challenges at http://www.aplusclick.com/money.htm